NOirni AMEUICAN COLKOrTKRA. •>( 



than lonfj at middle, distinctly narrowed at apex, moderately deeply emarjiinate. 

 the angles distinctly prominent to the front, sides regularly arcuate, hind angles 

 rectangular, disc, moderately convex, with two moderately deep, coarsely punc- 

 tured impressions on each side, the inner larger. Elytra not wider at base than 

 the base of the thorax, moderately deeply striate, striae finely cretiately punc- 

 tured, intervals convex. Body beneath usually paler than above ; sides of meta- 

 sternum and first two ventral segments with a few coarse punctures. Length 

 .:20— .28 inch. ; .') 7 mm. 



The scutelhir stria i.s always long and deeply impressed and free 

 at its apical end. The ocellate punctures are interrupted at the 

 middle of their extent. 



In this .siiecies both sexes have a shining surface. 



From all the species of this group the present may be known by 

 the very distinctly emarginate apex of the thorax with the angles 

 prominent to the front. 



A recent examination of the type shows that jjallid^da Cas. is 

 really a very immature specimen of this species and not of riibrica. 



Occurs in the Lake Sup. region, and in Nebraska and Colorado. 



A. rnbrica Hald.— Oblong, moderately convex, rufo-testaceous to castane- 

 ous, shining in both sexes. Antennse pale. Head smooth, frontal impressions 

 feeble and indistinct. Thorax not twice as wide as long, very little narrowed in 

 front, apex very feebly emarginate, sides regularly arcuate, hind angles usually 

 very obtuse, disc convex, the basal impression very feeble, usually punctured, 

 som'etimes entirely smooth. Elytra very little wider at base than the thorax, 

 moderately deeply striate, striae finely cretiately punctured, intervals convex. 

 Body beneath paler than above ; side of metaslernum and the met-episterna with 

 coarse punctures. Ventral segments coarsely sparsely punctate at the sides of 

 the first four segments ; legs pale rufo testaceous. Length .28— .28 inch. : 6—7 mm. 

 The scuteilar stria is long and deej), free at its apical end. The 

 series of ocellate punctures is interrujjted at middle. 



The punctuation in the basal region of the thorax is more variable 

 in this species than any of the group. Those with the smooth base 

 of the thorax bear su(;h a remarkable resemblance to less mature 

 forms of llnrpalm niUdulus that they might readily be confused. 

 The stria" arc rather more strongly crenate than in any other of the 

 group. The sculpture of the underside of the body will separate 

 from vinsculns, the only one which might be mixed with it. 

 Occurs from the :\Iiddle States region to Texas and Colorado. 



A. musfulus Say.~01)longoval, rufo-piceous. orpiceousand shining, some- 

 time's a faint seneous surface lustre. Antennae pale. Head smooth, frontal im- 

 jiressions almost entirely obliterated. Thorax rather more than half wider than 

 long, distinctly narrowed in front, apex very feebly emarginate, sides arcuate, 

 hind angles usually obtuse, sometimes subrectangular, disc convex, the basal de- 



TRANS. AM. KNT. .SOC. XIX. MAKCH. 1892. 



